Extraction, preparation, sensory evaluation and sweet perception of Stevia rebaudiana based food products

Abstract

Stevia rebaudiana (S. rebaudiana) is a shrub is a naturally sourced zero-calorie sweetener. The present study aimed at extracting sweetness components, preparation, standardization, & sweet perception of S. rebaudiana grown under the existing climatic conditions of Tarnab, Peshawar. The S. rebaudiana extract was prepared by dissolving 74 grams of stevia leaves powder in1000ml of distilled water and purification with calcium hydroxide. A total of twelve food products were developed by using sucrose as control and stevia extract as an experimental sweetener. Sensory evaluation for overall acceptability of the products were evaluated by 10 trained panelists using a 10 points hedonic scale. On the basis of sensory tests three products were rejected due to strong flavor and taste of chlorophyll still present. The data showed the overall acceptability score for control halwa was 8.12 ±0.67 as against 6.78 ±0.37 for stevia halwa with highly significant value of 0.000 and percent difference of 16.5%. Overall acceptability for control pancakes were 7.71 ±0.58 as against 6.62 ±0.64 for stevia sweetened pancakes and for control cookies 7.25 ±0.33 as against 6.93 ±0.96 for stevia cookies with non-significant difference. Perception of sweetness for stevia extract in comparison of sugar solution was done by threshold test. Highest perception was reported for 5mL/1000 mL water being equivalent to a sugar solution of 10 grams/100mL water. The duration of sweetness stimulus was greater for stevia (lasted 40 seconds) than for sucrose.

Sensory Evaluation of Brewed Black Tea (Camellia sinensis sp) and Stevia (Stevia rebaudiana Bert) Leaves. Case Study: Threshold of Phenolic Bitterness Consumer Preference Test

“…While sweetness has a perception duration of between 20-40". Somewhat similar to what has been conveyed by Savita [20] and Fatima [21], stevia sweet taste longer than sucrose. The astringency sensation impression from stevia solution was stronger than the sensation in blacktea solution.…”